Heating furnace



1,455,267 c. A. ROHN HEATING FURNACE Filed Feb. 1 192-2 2 Sheets-Sheet 1 May 15, 1923.

O O O I I 1 I i v my N mmw ATRNY.

C A. ROHN HEATING FURNACE Filed Feb. 10 1922 2 Sheets-Sheet 2 5%.17072/2. INVENTOR.

Patented May 15, 1923..

its

. CURTIS A. BOHIYL OF PORTLAND, OREGON.

HEATING summon.

Application filed February 10, 1922. Serial No. 535,598.

To collwhom it may concern Be it known that I, Cmrrrs A. Form, a citizen of the United States, residing at Portland, in the county of Multnomah and State of Oregon, have invented certain new and useful Improvements in Heating Furnaces, of which the following is a specification.

This invention relates to heating furnaces, and has for one of its objects to provide a simply constructed device of this character which may be quickly and easily arranged for burning either coal or wood and without detaching any of the parts of the furnace proper.

Another object of the invention is to provide a device of this character wherein the grate surface or area may be readily controlled to increase or decrease the size of the fire.

With these and other objects in view, the

described and then specifically pointed out in the claims, and in the drawings illustrative of the preferred embodiment of the invention:

Figure 1 is a vertical sectional elevation.

Fig. 2 is a vertical section on the line 2-2 of Fig. 1.

Fig. 3 is a transverse section on the line 3--3 of Fig. 1.

Fig. 4 is a transverse sectional detail illustrating the arrangement and operation of the cut off or grate surface area. controlling member.

Fig. 5 is a section on the line 5-5 of Fig.

The improved furnace comprises a shell or casing 10 having a fire chamber produced by fire plates 11, an ash pit 12, a grate 13, fire door 14, ash pit door 15, heat radiating drum 16, and smoke flue 17, these parts being of the usual construction.

An outer casing or envelope 18 is also generally employed in connection with fun naces of this class, with the firing and ash pit doors 14 and 15 leading through. the outer shell. I

The flue through which the air from the door 15 passes to the ash pit and thence through the grate when coal is used as a fuel, is represented at 19. and leading from this intake flue is a branch flue 2O communicating with the lower portion of the fire chamber just above the grate. When coal is used as a fuel the branch fine 20 is practically without function, but when wood is used as a'fuei and the openings in the grate are not required, an imperforate cut off plate represented at 21, is disposed over the grate and shuts off the passage of air upwardly therethrough; thereafter the only air which reaches the fuel passes through the branch flue S20 and in contact with the fuel on the shut off plate, the latter thus becoming the bed of the fire chamber.

By this means the furnace can be quickly transformed from a coal burner to-a wood burner by simply inserting the shut ofi plate 21, or quickly transformed from a wood burner to a coal burner by removing the shut off plate. No other change is required.

Extending inwardly from the side walls of the fire chamber are a plurality of spaced lugs 22 to provide supports for a transverse stop plate 23 whereby the area of the fire chamber may be controlled and increased or decreased as required.

If the whole of the grate surface is required for fuel, the shut off plate member 23 will not be required, but if a smaller fire is required the member 23 is located in position at any required point within the range of the lugs '22 and thus correspondingly limit the area of the grate.

Tlie improved device is simple in construction, can be inexpensively manufactured, and adapted to any of the different forms of furnace fire pots and ash pits without material structural change.

The preferred embodiment of the invention is disclosed in the drawings and set forth in the specification, but it will be understood that modifications within the scope of the claimed invention may be made in the construction without departing from the principle of the invention or sacrificing any of its advantages.

Having thus described the invention, what is claimed as new is 1. In a furnace including a fire chamber. ash pit, and a grate between the fire chamher and ash pit, an intake for air leading into the ash pit, a flue providing communication between the, air intake and the fire chamber, and an imperforate plate adapted to be disposed upon the grate to cut off the passage of air therethrough.

2. In a furnace including an ash pit, a fire chamber, a grate between the fire chamber and ash pit, said fire chamber having adapted to be movably disposed upon the grate, and a vertical member engaged With the seats and bearing at 1ts lower edge upon the plate, to control the area of the fire cham ber. V

3.. Ina furnace including a fire chamber, ash, pit, and grate between the firechamber and ash plt, saidfire chamber having spaced lugs extending inwardly from its side Walls, an intake for air leading into the ashpit, a branch flue providing communication between the air intake and the fire chamber, an imperforate member adapted to be disposed upon the grate to cut off the passage of air therethrough, and a stop member supported by said lugs, to control the area of the fire chamber.

In testimony whereof, I aflix my signature hereto. 7

CURTIS A. Rona}, 

